Quote Originally Posted by Tim K View Post
I've heard this, too, but don't know if it's true. I suspect it may not be. We're i a smith, I'd take a cheap barrel and cut it back an inch at a time and measure velocities. I'd like to know.
merely posts I pulled from other boards:

"Bob Milek wrote an article titled: BARREL LENGTH VS VELOCITY, where he took a number of barrels and guns and cut down the barrels in one inch increments, measuring the velocity loss at each step of the process for a number of centerfires as well as the 22LRs. It's a very interesting article. Here are the velocities recorded for the 22LR starting at 14 inches and going down to 4 inches.

14" = 1,105 fps.
13" = 1,106
12" = 1,110
11" = 1,089
10" = 1,114
..9" = 1,077
..8" = 1,063
..7" = 1,057
..6" = 1,024
..5" = ..959
..4" = ..927 fps."


"
http://www.rimfirecentral.com/forums...hortest+barrel
"24-26 in bbls are good/required to attain max-velocity for these 'hyper-velocity' rounds. Otherwise, 16 in or so is good for non-hypervelocity stuff."
"22 LR has burnt up it's powder in the first 4.5", however, it will still gain velocity past that. Anything more than a 20" barrel and you are loosing velocity."
Then someone calls BS on the "all powder is burned up in 4.5 inch" thing.
On the 2nd page there is a graph that may be worth looking at (chamber pressure v. barrel length).

From WikiPedia (fact? fiction? anecdotal? You decide) :-)
http://en.wikipedia.org/wiki/.22_Long_Rifle
"Most .22 Long Rifle powders increase velocity up to about 19 inches (480 mm) of barrel length; the powder used in the Stinger increases velocity up to the longest .22 barrel length tested by the NRA, 26 inches (660 mm)."